<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }

        div:hover {
            /*margin: 30px 0 0 30px;*/
            /*参照物是初始位置*/
            position: relative;
            top: 20px;
            left: 20px;
        }
    </style>
</head>

<body>
<div>div1</div>
<div>div2</div>
<div>div3</div>
</body>
</html>